Agreed. Traveling with kids and doing things like this is largely a personal decision, but I and many people I know have not had an issue re-clearing securit, in the terminal you land at, to use lounges. I wonder if this may be an issue originating LHR and departing T5 but opting for T3 lounges. I suspect that would not be allowed but I don't know from experience.

You are not legally allowed to be airside (in the departures area) of T3 if you don't have a flight departing from there. The layout of the terminal (specifically, transit desks being after the security checkpoint and in the general departures area) means that in practice it is usually possible to get through and do what you propose. That said, it's really not a great idea. I wouldn't wish unnecessary interactions with LHR security on anyone.

Hello guys,

I have an arrival in T5 and an AA departure in T3 8 hours later, so will be leaving the airport...

Is there a way for me to get my AA boarding pass before leaving the airport? I believe if I take the T3 transfer buses, I will be in T3 airside at the transfer desks.

Of course the simplest option would be to leave T5 and when I return, go to the checkin desks at T3, but with a 3 year old with us, would rather have the boarding passes with us beforehand

It is very likely that BA will be able to issue your AA boarding passes whenever you check in at your origination point.

Actually that is very unlikely. AA like to check documents themselves before issuing any bp.

There are some AA agents now near where you get the airside bus. I am not sure whether they can do the document check and issue the bp though. If they can you can go via the connection route, get the bp there, use the airside but to T3, and then proceed to go out to the border there - do not follow the signs for connections or go through security.

There is also a large room with aa agents doing document checks and issuing bp there just before security, again you could use the airside bus to get there, get your bp, and then as before head out to the border rather than go landside.

Tbh though this will mean you will take longer to leave LHR as you couldn't simply get the tube/HEX from T5 and head in to London. Considering when you come back you aren't really having to deviate much to go to the AA check in desks I think you may be better off just sorting it on your return.

In my experience, what is most likely to happen, is that BA will issue an BP for the AA flight at check-in. The flyer will then take that BP to the AA document checkers (and get the absurd "security questions") at whatever point OP encounters said AA checkers.

At least that's whats happened every time I've flown a BA to AA connection at LHR.

AA's not going to let you board the plane at LHR until they've done a doc check and security theatre, but that doesn't mean BA can't print a BP.

* EDIT: the above assumes OP is on a single PNR, which upon review was not clear from the OP.

That's my experience too.

I would not recommend attempting this unless you are already intimately familiar with the layout of terminal 3. The terminal exits are not sign posted.

Fair enough. It isn't my experience.

Then why do Heathrow offer an inter-terminal escort service in order to facilitate high value customers shopping in a different terminal?

It might be frowned upon or disliked by HAL, but I doubt it is illegal.

I think someone once produced some LHR bye-law that said something along the lines of "you must follow all airport signs" and then extrapolated to suggest by deliberately going in a direction contrary to the signs for connections you were breaking the law. Seemed pretty tenuous to me.

I would agree with your earlier post, this shouldn't be attempted unless you really do know where you are going, and even then would the CX lounge admit you if you have a bp for a flight departing from another terminal?

Sure, I oversimplified it; if you have permission from an authorised person it becomes legal. It's in ANTA (Air Navigation and Transport Act) somewhere; I'll look it up when I've time.

May not be the right place for this, but can you get a porter in T3 inside the sterile area before exiting customs?

Yes. One can do this in the "room" mentioned above or, if the line looks too long, simply do it at the desk after security and, if it looks too long there, do it at the gate. Because most people will have been caught up previously, it is now very fast at the gate due to few people doing it.

Cheers.

If you're arriving at LHR T3 and leaving the airport, you don't go into the sterile area.